Structural basis of transcriptional regulation by a nascent RNA element, HK022 putRNA.

ABSTRACT: Transcription, in which RNA polymerases (RNAPs) produce RNA from DNA, is the first step of gene expression. As such, it is highly regulated either by trans-elements like protein factors and/or by cis-elements like specific sequences on the DNA. Lambdoid phage HK022 contains a cis-element, put, which suppresses pausing and termination during transcription of the early phage genes. The putRNA transcript solely performs the anti-pausing/termination activities by interacting directly with the E.coli RNAP elongation complex (EC) by an unknown structural mechanism. In this study, we reconstituted putRNA-associated ECs and determined the structures using cryo-electron microscopy. The determined structures of putRNA-associated EC, putRNA-absent EC, and σ⁷⁰-bound EC suggest that the putRNA interaction with the EC counteracts swiveling, a conformational change previously identified to promote pausing and σ⁷⁰ might modulate putRNA folding via σ⁷⁰-dependent pausing during elongation.

SUBMITTER: Hwang S 

PROVIDER: S-EPMC9378689 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature